Parts of the Body Affected by Cystic Fibrosis (CF)

Cystic Fibrosis (CF) affects the exocrine glands, which are organs that secrete mucus. Exocrine glands normally produce thin, slippery secretions such as mucus, sweat, tears and digestive juices. With cystic fibrosis, the mucus is thick and sticky. This unusually thick mucus interferes with the normal functioning of certain body systems.

The parts of the body most affected by cystic fibrosis are the sweat glands, respiratory system, digestive system and reproductive system. Cystic fibrosis does not, however, effect the brain and nervous system. A child's ability to learn is not altered by having cystic fibrosis. Treatments are available to take care of symptoms in affected systems.

Sweat Glands

In people with cystic fibrosis, the amount of body salts (sodium and chloride) lost in the sweat is elevated. This can cause problems during times of increased sweating, such as during exercise and hot weather.

Respiratory System

The respiratory system is divided into the upper respiratory and lower respiratory tracts. The upper respiratory tract includes the nasal passages and sinuses. The lower tract is shaped like an upside-down tree with progressively smaller branches.

The lower tract consists of the trachea (main air passage), bronchi (two large air passages), bronchial tubes (smaller air passages) and alveoli (air sacs). Tiny, hair-like cells (the cilia) keep the lungs clean and clear. Lining the lower respiratory tract, the cilia move dust, germs and mucus from the smaller passages to the larger ones, where they can be coughed out. The respiratory system mainly functions to bring oxygen into the body and remove carbon dioxide, a waste gas.

In a person with cystic fibrosis, the cilia cannot easily move the thick and sticky mucus out of the smaller passages. The mucus clogs the air passages, causing a chronic cough and lung infections. Repeated lung infections can lead to lung damage, causing breathing problems and difficulty getting enough oxygen into the body.

Digestive System

The digestive system, or the gastrointestinal tract, consists of organs involved in digesting food. In the mouth, food is chewed and mixed with saliva. After passing through the esophagus into the stomach, the food mixes with stomach juices that further break down the food.

Partially digested food enters the small intestines, where it mixes with enzymes secreted by the pancreas and with bile, which is made in the liver and stored in the gallbladder. These enzymes finish the digestive process. As the digested food passes through the small intestines, the blood stream absorbs nutrients and takes them to other parts of the body.

The remaining undigested parts, such as fiber, pass into the large intestine, where water is absorbed. Undigested food and waste collect in the rectum, eventually leaving the body as stool.

In a person with cystic fibrosis, the thick and sticky mucus blocks the pancreatic ducts, preventing the enzymes from reaching the small intestine to digest food. The result is incomplete digestion, poor absorption of nutrients and large, loose, foul-smelling stools. This condition - pancreatic insufficiency - occurs in about 85 percent of people with cystic fibrosis.

Reproductive System

People with cystic fibrosis are born with normal external reproductive organs. As adults they have the capacity to have intercourse but may have fertility problems. About 95 percent of men and 20 percent of women with cystic fibrosis are infertile.

In men, the vas deferens, the tube that normally carries the sperm from the testicles to the penis, may be blocked or defective. Therefore, a man with cystic fibrosis can experience a normal erection and ejaculation, but the semen may contain no sperm.

In women, fertility problems result from thick mucus blocking the cervix, which is the opening to the uterus. This blockage prevents the sperm from reaching the egg for fertilization.